With calving just getting underway for many producers pre breeding checks on bulls and females may be the furthest thing from many people’s minds. However, by having a pre breeding examination carried out on breeding bulls up to 8 weeks before the bulls are due to go out with the cows you can save yourself the stress of finding out later that the bull was not fit for the job.
The main objective of a Bull Breeding Soundness Examination (BBSE) is to identify bulls that are potentially unfit for breeding in good enough time to allow for retesting and /or finding a suitable replacement to ensure that a compact calving period and herd efficiency is not impacted.
A bull with normal fertility is defined as being able to run with 30-40 cycling cows and achieve a 94% pregnancy rate in a nine week mating period, a sub fertile bull would be able to achieve pregnancies in low pressure situations such as low bull to cow ratios and extended mating periods but this would result in a disrupted calving period and ongoing reproductive inefficiency.
What Is The BBSE?
The BBSE is a three stage examination carried out by your vet. The three stages are:
- General Physical examination – locomotion – considerations include whether bulls feet may need trimmed or if there is lameness that is attributed to a musculoskeletal problem that may make the bull unfit to serve cows, body condition score – ideally looking for a BCS of 3 – ‘fit not fat’.
- Genital Examination including accessory glands – scrotal size will be measured as this directly related to sperm output and is also correlated with the age at puberty of female offspring, which is useful if selecting bulls to sire replacement females.
- Electro Ejaculation and semen evaluation – done in handling crate and evaluated on farm.
It should be kept in mind that libido and ability to serve are not directly assessed, so bulls should be observed serving cows and you should look out for problems e.g. penis deviation (corkscrew penis) or warts. As a rule of thumb, if a bull is put with a cow in heat then he should serve her within 20 minutes and ideally within 10 minutes.
Bulls can be transiently infectious (including semen) after recent exposure to a disease. It is very important to ensure that all routine vaccinations (e.g. BVD, IBR, Leptospirosis) and routine treatments for liver fluke, worms and external parasites (e.g. flies, lice) are up to date.
If the bull is hired or has worked in other herds ask your vet to sheath wash them, as those bulls carry an increased risk of introducing diseases including Campylobacter.
If it has been identified that the bull needs his feet trimmed ensure this is done with plenty time for recovery (up to 8 weeks prior to being needed) to ensure the bull is feeling fit enough to chase cows.
In addition to the bulls it may be worth considering having a pre breeding check on the heifers in your herd where your vet could pelvic measure, check that the ovaries are cycling and identify any potential non breeders (e.g. twin to bull).
Nearer the time of putting the bulls out with the cows it may be worthwhile looking at the ‘high risk’ cows in the herd – those that had difficult calvings, caesareans, retained placentas etc. to ensure that they are back cycling and have no ongoing internal issues that may hinder their ability to get back in calf.
It is worth discussing your farm’s needs with your vet to ensure that an appropriate course of action is undertaken with regards the fertility of your herd.
Lesley Wylie, firstname.lastname@example.org
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